U.S. patent number 5,257,077 [Application Number 07/829,094] was granted by the patent office on 1993-10-26 for toner dispensing apparatus for a xerographic reproduction machine.
This patent grant is currently assigned to Xerox Corporation. Invention is credited to Anthony C. Fornalik, Henry B. Peters, Jr., John M. Wysocky.
United States Patent |
5,257,077 |
Peters, Jr. , et
al. |
October 26, 1993 |
Toner dispensing apparatus for a xerographic reproduction
machine
Abstract
A toner cartridge is provided for dispensing toner on demand to
the development station of a xerographic copier machine. The
cartridge is modified so as to improve the dispensing of toner
through dispensing ports located at one end of the cartridge by the
provision of a relatively stiff, coiled spring element which is
fixed in position adjacent the interior walls of the cartridge. As
the cartridge rotates, the spring moves through the toner acting as
an auger-type transport mechanism to move the toner towards the
dispensing ports. The spring also serves to agitate the toner so as
to make its consistency more fluid thereby aiding the augering
transport motion. In one embodiment, the toner cartridge is tilted
so as to utilize additional gravitational forces to assist in the
toner transport towards the dispensing end.
Inventors: |
Peters, Jr.; Henry B. (Webster,
NY), Wysocky; John M. (Rochester, NY), Fornalik; Anthony
C. (Webster, NY) |
Assignee: |
Xerox Corporation (Stamford,
CT)
|
Family
ID: |
25253508 |
Appl.
No.: |
07/829,094 |
Filed: |
January 31, 1992 |
Current U.S.
Class: |
399/263;
222/DIG.1 |
Current CPC
Class: |
G03G
15/0877 (20130101); G03G 15/0868 (20130101); G03G
2215/0665 (20130101); G03G 2215/0675 (20130101); Y10S
222/01 (20130101); G03G 2215/0685 (20130101) |
Current International
Class: |
G03G
15/08 (20060101); G03G 015/06 () |
Field of
Search: |
;355/260 ;222/DIG.1 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Grimley; A. T.
Assistant Examiner: Ramirez; Nestor R.
Claims
What is claimed is:
1. In a xerographic reproduction machine which includes:
a movable recording member on which latent electrostatic images are
created,
developing means for developing said images with toner, and
transfer means for transferring the developed images to a copy
substrate material,
said developing means including a developer housing adjacent said
recording member with means in said housing to bring developer from
a sump in said housing into developing relation with said recording
member to develop images on said recording member, said developing
means characterized by including a toner dispensing apparatus for
periodically dispensing toner into said sump comprising in
combination:
a cylindrical toner cartridge enclosed at both ends and positioned
above said sump and containing a supply of toner therein, said
cartridge having a plurality of toner discharge ports located along
the length of the cartridge,
drive means for periodically rotating said cartridge, and
a single relatively stiff, coiled spring member having a coil
diameter slightly less than the diameter of the cartridge thus
causing the spring member to remain fixedly in place along the
length of the cartridge and contacting the inside wall surfaces of
the cartridge, said coiled spring member adapted to transport the
toner within the cartridge towards the discharge ports during
rotation of the cartridge while simultaneously mixing the toner and
making the consistency of the toner more fluid like.
2. The reproduction machine of claim 1 wherein said coiled spring
member is positioned so as not to overly any of said discharge
ports.
3. The reproduction machine of claim 1 wherein said coiled spring
member has a plurality of coils separated from each other by a
pitch distance P between a range of 10 and 75 mm.
4. The reproduction machine of claim 1 further including means for
rotating said cartridge on a periodic, on-demand basis.
5. The reproduction machine of claim 1 wherein said toner cartridge
is aligned in a horizontal plane.
6. The reproduction machine of claim 1 wherein said cartridge is
aligned along a plane at an angle to the horizontal with the toner
discharge ports being below the horizontal.
Description
BACKGROUND AND MATERIAL DISCLOSURE STATEMENT
The present invention relates to a toner dispenser in a xerographic
reproduction machine developer station and, more particularly, to a
rotating dispenser which incorporates a fixed internal helical-type
spring to improve the toner dispensing.
In prior art xerographic reproduction machines, the toner material
used to develop a latent image formed on a photoreceptor surface is
consumed in a development process and must be periodically replaced
within the development system in order to sustain continuous
operation of the machine. One technique which has become generally
accepted is the use of a separate toner or developer hopper
incorporating a toner cartridge for dispensing the toner into a
hopper on a continuous, or on an on-demand basis. In addition, it
has become common practice to use a toner cartridge, which, when
placed in the machine, can be automatically opened to dispense
toner. In such systems, a difficulty may arise in uniformly
dispensing the toner from the cartridge, since the toner particles
may tend to agglomerate, become compacted, and form a bridging
structure in the toner container.
Various techniques have been developed to enable a reliable
dispensing of toner from toner cartridges. U.S. Pat. Nos. 4,951,094
and 4,969,011 disclose toner developing systems in which toner
cartridges are periodically rotated so that toner is dispensed
through a series of ports extending along the length of the
cartridge. U.S. Pat. Nos. 4,739,907; 4,943,830; and 3,724,725
disclose dispensing systems wherein the toner cartridge is
stationary and an internal coil member is rotated to order the
toner to a dispensing end, the rotating member additionally serving
an anti-bridging function. U.S. Pat. No. 4,965,639 discloses a
rotating cartridge which is slightly inclined to the horizontal so
that toner is gravity-fed to dispensing ports located at one end.
This system, however, lacks a toner transport and an anti-bridging
mechanism.
The present invention is directed towards a dispensing system which
dispenses toner on demand. The dispensing system includes a toner
cartridge, which is periodically rotated to dispense toner through
an exit port at a dispensing end. The toner in the cartridge is
transported towards a dispensing end, while simultaneously being
mixed and fluffed to assist such transport, by the action of an
internal, coiled spring, which is held in place along the interior
surface of the cartridge. As the cartridge rotates, the spring acts
to both auger the toner towards the dispensing end and to keep the
toner in a fluid-like condition to assist the toner movement
towards the dispensing end. More particularly, the present
invention relates to a xerographic reproduction machine which
includes:
a movable recording member on which latent electrostatic images are
created,
developing means for developing said images with toner, and
transfer means for transferring the developed images to a copy
substrate material,
said developing means including a developer housing adjacent said
recording member with means in said housing to bring developer from
a sump in said housing into developing relation with said recording
member to develop images on said recording member, said developing
means characterized by including a toner dispensing apparatus for
periodically dispensing toner into said sump comprising in
combination:
a cylindrical toner cartridge positioned above said sump and
containing a supply of toner therein, said cartridge having a
plurality of toner discharge ports at one end thereof,
drive means for periodically rotating said cartridge, and
a relatively stiff, coiled spring member fixedly attached along the
interior surface of the cartridge and extending along the length of
the cartridge, said spring element adapted to transport the toner
within the cartridge towards the dispensing end during rotation of
the cartridge while simultaneously mixing the toner and making the
consistency of the toner more fluid-like.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a reproduction machine incorporating the
toner dispensing apparatus of the present invention.
FIG. 2 is a side view of one of the toner dispensing cartridge of
FIG. 1 showing the arrangement of an internally located augering
spring.
DESCRIPTION OF THE INVENTION
Referring to FIG. 1 of the drawings, there is shown a xerographic
type reproduction machine 8 incorporating the toner dispensing
apparatus of the present invention. Machine 8 has a suitable frame
(not shown) on which the machine xerographic components are
operatively supported. Briefly, and as will be familiar to those
skilled in the art, the machine xerographic components include a
recording member, shown here in the form of a rotatable
photoreceptor 12. In the exemplary arrangement shown, photoreceptor
12 comprises a drum having a photoconductive surface 14.
Operatively disposed about the periphery of photoreceptor 14 are a
charge corotron 18 for placing a uniform charge on the
photoconductive surface 14; an exposure station 20 where the
previously charged photoconductive surface 14 is exposed to image
rays of a document 16 being copied or reproduced; development
station 22 where the latent electrostatic image created on
photoconductive surface 14 is developed by toner; and transfer
detack corotrons 24 and 26 for assisting transfer of the developed
image to a suitable copy substrate material such as a copy sheet 28
brought forward in timed relation with the developed image on
photoconductive surface 14. Residual toner is removed from the drum
surface at cleaning station 36.
Following transfer, the sheet 28 is carried forward to a fusing
station where the toner image is fixed by fusing roll pair 34.
After fusing, the copy sheet is discharged to an output tray (not
shown).
A transparent platen 40 supports the document 16 as the document is
moved past a scan point 42 by a constant velocity type transport
44. As will be understood, scan point 42 is in effect a scan line
extending across the width of platen 40 at a desired point along
the platen where the document is scanned line by line as the
document is moved along platen 40 by transport 44. Exposure lamp 46
is provided to illuminate a strip-like area of platen 40 at scan
point 42. The image rays from the document line scanned are
transmitted by a gradient index fiber lens array 50 to exposure
station 20 to expose the photoconductive surface 14 of the moving
photoreceptor 12.
Developer station 22 includes a developer housing 60 in which a
toner dispensing cartridge 62, containing preloaded toner particles
63, is rotatably mounted to turn in the indicated clockwise
direction so as to dispose toner particles contained therein into a
sump area 65, in which are positioned a pair of rotatably mounted
augers 64, 66. The augers conventionally mix the toner with a
developer mixture within the sump and transport the developer into
the vicinity of magnetic brush applicator brush 68, which applies a
developer mixture to the latent image formed on the photoconductive
surface. Further details of the operation of the augers and the
magnetic brush applicator are found in U.S. Pat. No. 4,978,997,
whose contents are hereby incorporated by reference.
As shown in end view in FIG. 1 and in cross-sectional side view in
FIG. 2, a stiff spring element 70 is fixedly positioned along the
inside length of cartridge 62. Referring to FIG. 2, cartridge 62 is
enclosed at both ends by end caps 62A, 62B. A series of dispensing
ports 72 are located at one end of cartridge 62. The cartridge is
rotated by a motor 74 attached to shaft hub 76. A magnet 78 is
attached to the outside of end cap 62A. A magnetic switch 80 is
positioned to be in line with magnet 78 on each rotational cycle.
Each time the cartridge completes a full rotation, a signal is sent
from switch 80 to controller 82 which delays the next cartridge
rotation for some predetermined time period. Controller 82 also
operates in a predetermined relationship with other components of
machine 8 to control machine functions and timing as disclosed in
aforementioned U.S. Pat. No. 4,978,997.
Spring 70 comprises a coiled, relatively stiff, spring-like member
which is attached to the inside end cap 62A of the cartridge by
filament tape or the like. Once attached to the end cap, the coiled
spring remains fixedly in place along the length of the cartridge
contacting the inside wall surfaces of the cartridge. The diameter
of spring member 70 is selected to be slightly less than the
diameter of cartridge 62 to provide a snug fit along the length of
the cartridge. A preferred material for spring 70 is metallic or
toner-compatible plastic. The pitch distance P between the coils of
spring 70 has been set at some optimum distance, in this case 35 mm
but a range of between 10 and 75 mm would provide optimum toner
mixing and transport. The cross-sectional diameter of the wire is
preferably within 2 and 4 mm. Still referring to FIG. 2, the spring
70 is fixed to end cap 62A so as not to cover any of the dispensing
ports 72.
In operation, as the cartridge turns through a dispensing cycle,
the toner is transported towards the dispensing end by the augering
action of spring 70 as it is turned along with the cartridge.
Spring 70 also serves a second function, that of continually
slicing through the toner 63 as it collects at the bottom of the
cartridge to maintain the toner in a fluffed and more fluid-like
consistency, thereby enabling a better "flow" of the toner towards
the dispensing end.
While the embodiment shown in FIGS. 1 and 2 utilized a toner
cartridge fixed in a horizontal plane, the invention may also be
used with a cartridge which is slightly tilted about a midpoint,
with respect to the horizontal. The dispensing port sector 72A
would be selected so that that end of the cartridge is below the
horizontal. With this embodiment, a gravitational force cooperates
with the augering action of the spring to move the toner towards
the dispensing port sector 72A. An additional advantage of this
embodiment is a relaxation of the tolerances which must be observed
in initial leveling of the machine frame 8.
While the invention has been described with reference to the
structures disclosed, it is not confined to the details set forth,
but is intended to cover such modifications or changes as they come
within the scope of the following claims. Although the preferred
embodiment calls for a coiled spring-like member, the invention may
be practiced, albeit, less efficiently, with a transport and mixing
member or plurality of members comprising segmented, linear coils
which are fixed in place along the interior circumference of the
cartridge. This configuration, however, while it provides the
mixing action, does not provide the required augering action.
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